This invention relates to cutting apparatus and more particularly to an oscillating knife cutter having particular utility in agricultural equipment such as a forage harvester, combine and the like.
Oscillating knife cutters, as used on a row crop harvesting unti of a forage harvester, are used to sever the forage initially in its standing position in the field as the forage is being taken into the harvester by the feeding mechanism of the row crop unit. Prior art designs of such cutters for forage harvesters have proved to be unsatisfactory due to poor durability, to the high cost of repair and to the difficulty of making adjustments of the knives of the cutter periodically during use. In one commercial prior art design (shown in FIGS. 1-3 herein), the cutter includes a main support with a pair of main knives fixed thereon. A stationary central shaft is permanently fixed to the main support. A secondary support with a knife fixed thereto is rotatably mounted on the shaft for movement relative to the main support. Adjustment of the main knives relative to the secondary knife is made by shims positioned between each main knife and the main support. The central shaft for supporting the secondary knife is subject to high wear in the area adjacent the position of the secondary support. This condition is worsened because of the exposure of the apparatus to dirt and other foreign matter during use of the knife. After excessive wear of the shaft, repair of the cutting apparatus requires replacement of both the main support and the shaft causing an excessively high cost of repair.
Also, adjustment of the fixed main knives relative to the secondary oscillatory knife is difficult because of the placement of the cutter on the forage harvester underneath the row crop attachment. This placement requires the entire cutting apparatus to be removed from the harvester to permit access to the main knives for removal or changing of the shims for adjustment of the knives.
Accordingly, it is an object of this invention to provide an improved oscillating knife cutting apparatus.
Another object of this invention is to provide an oscillating knife cutting apparatus wherein the knives may be adjusted relative to each other in a simple manner.
Still another object of this invention is to provide a cutting apparatus with improved life and reduced repair costs.